Fixes missing overflow lint for i64 #14269

The `type_overflow` lint, doesn't catch the overflow for `i64` because
the overflow happens earlier in the parse phase when the `u64` as biggest
possible int gets casted to `i64` , without checking the for overflows.
We can't lint in the parse phase, so a refactoring of the `LitInt` type
was necessary.

The types `LitInt`, `LitUint` and `LitIntUnsuffixed` where merged to one
type `LitInt` which stores it's value as `u64`. An additional parameter was
added which indicate the signedness of the type and the sign of the value.

src/libfourcc/lib.rs

@@ -124,7 +124,7 @@ pub fn expand_syntax_ext(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
             (val << 8) | (byte as u32)
         };
     }
-    let e = cx.expr_lit(sp, ast::LitUint(val as u64, ast::TyU32));
+    let e = cx.expr_lit(sp, ast::LitInt(val as u64, ast::UnsignedIntLit(ast::TyU32)));
     MacExpr::new(e)
 }
 

src/librustc/lint/builtin.rs

@@ -135,7 +135,7 @@ impl LintPass for TypeLimits {
                 match expr.node  {
                     ast::ExprLit(lit) => {
                         match lit.node {
-                            ast::LitUint(..) => {
+                            ast::LitInt(_, ast::UnsignedIntLit(_)) => {
                                 cx.span_lint(UNSIGNED_NEGATE, e.span,
                                              "negation of unsigned int literal may \
                                              be unintentional");
@@ -177,15 +177,25 @@ impl LintPass for TypeLimits {
                         } else { t };
                         let (min, max) = int_ty_range(int_type);
                         let mut lit_val: i64 = match lit.node {
-                            ast::LitInt(v, _) => v,
-                            ast::LitUint(v, _) => v as i64,
-                            ast::LitIntUnsuffixed(v) => v,
+                            ast::LitInt(v, ast::SignedIntLit(_, ast::Plus)) |
+                            ast::LitInt(v, ast::UnsuffixedIntLit(ast::Plus)) => {
+                                if v > i64::MAX as u64{
+                                    cx.span_lint(TYPE_OVERFLOW, e.span,
+                                                 "literal out of range for its type");
+                                    return;
+                                }
+                                v as i64
+                            }
+                            ast::LitInt(v, ast::SignedIntLit(_, ast::Minus)) |
+                            ast::LitInt(v, ast::UnsuffixedIntLit(ast::Minus)) => {
+                                -(v as i64)
+                            }
                             _ => fail!()
                         };
                         if self.negated_expr_id == e.id {
                             lit_val *= -1;
                         }
-                        if  lit_val < min || lit_val > max {
+                        if lit_val < min || lit_val > max {
                             cx.span_lint(TYPE_OVERFLOW, e.span,
                                          "literal out of range for its type");
                         }
@@ -197,9 +207,7 @@ impl LintPass for TypeLimits {
                         let (min, max) = uint_ty_range(uint_type);
                         let lit_val: u64 = match lit.node {
                             ast::LitByte(_v) => return,  // _v is u8, within range by definition
-                            ast::LitInt(v, _) => v as u64,
-                            ast::LitUint(v, _) => v,
-                            ast::LitIntUnsuffixed(v) => v as u64,
+                            ast::LitInt(v, _) => v,
                             _ => fail!()
                         };
                         if  lit_val < min || lit_val > max {
@@ -294,9 +302,10 @@ impl LintPass for TypeLimits {
                     let (min, max) = int_ty_range(int_ty);
                     let lit_val: i64 = match lit.node {
                         ast::ExprLit(li) => match li.node {
-                            ast::LitInt(v, _) => v,
-                            ast::LitUint(v, _) => v as i64,
-                            ast::LitIntUnsuffixed(v) => v,
+                            ast::LitInt(v, ast::SignedIntLit(_, ast::Plus)) |
+                            ast::LitInt(v, ast::UnsuffixedIntLit(ast::Plus)) => v as i64,
+                            ast::LitInt(v, ast::SignedIntLit(_, ast::Minus)) |
+                            ast::LitInt(v, ast::UnsuffixedIntLit(ast::Minus)) => -(v as i64),
                             _ => return true
                         },
                         _ => fail!()
@@ -307,9 +316,7 @@ impl LintPass for TypeLimits {
                     let (min, max): (u64, u64) = uint_ty_range(uint_ty);
                     let lit_val: u64 = match lit.node {
                         ast::ExprLit(li) => match li.node {
-                            ast::LitInt(v, _) => v as u64,
-                            ast::LitUint(v, _) => v,
-                            ast::LitIntUnsuffixed(v) => v as u64,
+                            ast::LitInt(v, _) => v,
                             _ => return true
                         },
                         _ => fail!()

src/librustc/middle/const_eval.rs

@@ -560,10 +560,13 @@ pub fn lit_to_const(lit: &Lit) -> const_val {
         }
         LitByte(n) => const_uint(n as u64),
         LitChar(n) => const_uint(n as u64),
-        LitInt(n, _) => const_int(n),
-        LitUint(n, _) => const_uint(n),
-        LitIntUnsuffixed(n) => const_int(n),
-        LitFloat(ref n, _) | LitFloatUnsuffixed(ref n) => {
+        LitInt(n, ast::SignedIntLit(_, ast::Plus)) |
+        LitInt(n, ast::UnsuffixedIntLit(ast::Plus)) => const_int(n as i64),
+        LitInt(n, ast::SignedIntLit(_, ast::Minus)) |
+        LitInt(n, ast::UnsuffixedIntLit(ast::Minus)) => const_int(-(n as i64)),
+        LitInt(n, ast::UnsignedIntLit(_)) => const_uint(n),
+        LitFloat(ref n, _) |
+        LitFloatUnsuffixed(ref n) => {
             const_float(from_str::<f64>(n.get()).unwrap() as f64)
         }
         LitNil => const_nil,

src/librustc/middle/trans/consts.rs

@@ -47,9 +47,13 @@ pub fn const_lit(cx: &CrateContext, e: &ast::Expr, lit: ast::Lit)
     match lit.node {
         ast::LitByte(b) => C_integral(Type::uint_from_ty(cx, ast::TyU8), b as u64, false),
         ast::LitChar(i) => C_integral(Type::char(cx), i as u64, false),
-        ast::LitInt(i, t) => C_integral(Type::int_from_ty(cx, t), i as u64, true),
-        ast::LitUint(u, t) => C_integral(Type::uint_from_ty(cx, t), u, false),
-        ast::LitIntUnsuffixed(i) => {
+        ast::LitInt(i, ast::SignedIntLit(t, _)) => {
+            C_integral(Type::int_from_ty(cx, t), i, true)
+        }
+        ast::LitInt(u, ast::UnsignedIntLit(t)) => {
+            C_integral(Type::uint_from_ty(cx, t), u, false)
+        }
+        ast::LitInt(i, ast::UnsuffixedIntLit(_)) => {
             let lit_int_ty = ty::node_id_to_type(cx.tcx(), e.id);
             match ty::get(lit_int_ty).sty {
                 ty::ty_int(t) => {

src/librustc/middle/typeck/check/mod.rs

@@ -2057,9 +2057,9 @@ fn check_lit(fcx: &FnCtxt,
         }
         ast::LitByte(_) => ty::mk_u8(),
         ast::LitChar(_) => ty::mk_char(),
-        ast::LitInt(_, t) => ty::mk_mach_int(t),
-        ast::LitUint(_, t) => ty::mk_mach_uint(t),
-        ast::LitIntUnsuffixed(_) => {
+        ast::LitInt(_, ast::SignedIntLit(t, _)) => ty::mk_mach_int(t),
+        ast::LitInt(_, ast::UnsignedIntLit(t)) => ty::mk_mach_uint(t),
+        ast::LitInt(_, ast::UnsuffixedIntLit(_)) => {
             let opt_ty = expected.map_to_option(fcx, |sty| {
                 match *sty {
                     ty::ty_int(i) => Some(ty::mk_mach_int(i)),

src/librustdoc/clean/mod.rs

@@ -1947,8 +1947,6 @@ fn lit_to_string(lit: &ast::Lit) -> String {
         },
         ast::LitChar(c) => format!("'{}'", c),
         ast::LitInt(i, _t) => i.to_string(),
-        ast::LitUint(u, _t) => u.to_string(),
-        ast::LitIntUnsuffixed(i) => i.to_string(),
         ast::LitFloat(ref f, _t) => f.get().to_string(),
         ast::LitFloatUnsuffixed(ref f) => f.get().to_string(),
         ast::LitBool(b) => b.to_string(),

src/libsyntax/ast.rs

@@ -18,6 +18,7 @@ use parse::token::{InternedString, str_to_ident};
 use parse::token;
 
 use std::fmt;
+use std::num::Zero;
 use std::fmt::Show;
 use std::option::Option;
 use std::rc::Rc;
@@ -656,15 +657,46 @@ pub enum StrStyle {
 
 pub type Lit = Spanned<Lit_>;
 
+#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+pub enum Sign {
+    Minus,
+    Plus
+}
+
+impl<T: PartialOrd+Zero> Sign {
+    pub fn new(n: T) -> Sign {
+        if n < Zero::zero() {
+            Minus
+        } else {
+            Plus
+        }
+    }
+}
+
+#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+pub enum LitIntType {
+    SignedIntLit(IntTy, Sign),
+    UnsignedIntLit(UintTy),
+    UnsuffixedIntLit(Sign)
+}
+
+impl LitIntType {
+    pub fn suffix_len(&self) -> uint {
+        match *self {
+            UnsuffixedIntLit(_) => 0,
+            SignedIntLit(s, _) => s.suffix_len(),
+            UnsignedIntLit(u) => u.suffix_len()
+        }
+    }
+}
+
 #[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
 pub enum Lit_ {
     LitStr(InternedString, StrStyle),
     LitBinary(Rc<Vec<u8> >),
     LitByte(u8),
     LitChar(char),
-    LitInt(i64, IntTy),
-    LitUint(u64, UintTy),
-    LitIntUnsuffixed(i64),
+    LitInt(u64, LitIntType),
     LitFloat(InternedString, FloatTy),
     LitFloatUnsuffixed(InternedString),
     LitNil,

src/libsyntax/ext/build.rs

@@ -626,13 +626,13 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
         self.expr(sp, ast::ExprLit(box(GC) respan(sp, lit)))
     }
     fn expr_uint(&self, span: Span, i: uint) -> Gc<ast::Expr> {
-        self.expr_lit(span, ast::LitUint(i as u64, ast::TyU))
+        self.expr_lit(span, ast::LitInt(i as u64, ast::UnsignedIntLit(ast::TyU)))
     }
     fn expr_int(&self, sp: Span, i: int) -> Gc<ast::Expr> {
-        self.expr_lit(sp, ast::LitInt(i as i64, ast::TyI))
+        self.expr_lit(sp, ast::LitInt(i as u64, ast::SignedIntLit(ast::TyI, ast::Sign::new(i))))
     }
     fn expr_u8(&self, sp: Span, u: u8) -> Gc<ast::Expr> {
-        self.expr_lit(sp, ast::LitUint(u as u64, ast::TyU8))
+        self.expr_lit(sp, ast::LitInt(u as u64, ast::UnsignedIntLit(ast::TyU8)))
     }
     fn expr_bool(&self, sp: Span, value: bool) -> Gc<ast::Expr> {
         self.expr_lit(sp, ast::LitBool(value))

src/libsyntax/ext/bytes.rs

@@ -47,7 +47,7 @@ pub fn expand_syntax_ext(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                 }
 
                 // u8 literal, push to vector expression
-                ast::LitUint(v, ast::TyU8) => {
+                ast::LitInt(v, ast::UnsignedIntLit(ast::TyU8)) => {
                     if v > 0xFF {
                         cx.span_err(expr.span, "too large u8 literal in bytes!");
                         err = true;
@@ -57,13 +57,14 @@ pub fn expand_syntax_ext(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                 }
 
                 // integer literal, push to vector expression
-                ast::LitIntUnsuffixed(v) => {
+                ast::LitInt(_, ast::UnsuffixedIntLit(ast::Minus)) => {
+                    cx.span_err(expr.span, "negative integer literal in bytes!");
+                    err = true;
+                }
+                ast::LitInt(v, ast::UnsuffixedIntLit(ast::Plus)) => {
                     if v > 0xFF {
                         cx.span_err(expr.span, "too large integer literal in bytes!");
                         err = true;
-                    } else if v < 0 {
-                        cx.span_err(expr.span, "negative integer literal in bytes!");
-                        err = true;
                     } else {
                         bytes.push(cx.expr_u8(expr.span, v as u8));
                     }

src/libsyntax/ext/concat.rs

@@ -37,11 +37,14 @@ pub fn expand_syntax_ext(cx: &mut base::ExtCtxt,
                     ast::LitChar(c) => {
                         accumulator.push_char(c);
                     }
-                    ast::LitInt(i, _) | ast::LitIntUnsuffixed(i) => {
+                    ast::LitInt(i, ast::UnsignedIntLit(_)) |
+                    ast::LitInt(i, ast::SignedIntLit(_, ast::Plus)) |
+                    ast::LitInt(i, ast::UnsuffixedIntLit(ast::Plus)) => {
                         accumulator.push_str(format!("{}", i).as_slice());
                     }
-                    ast::LitUint(u, _) => {
-                        accumulator.push_str(format!("{}", u).as_slice());
+                    ast::LitInt(i, ast::SignedIntLit(_, ast::Minus)) |
+                    ast::LitInt(i, ast::UnsuffixedIntLit(ast::Minus)) => {
+                        accumulator.push_str(format!("-{}", i).as_slice());
                     }
                     ast::LitNil => {}
                     ast::LitBool(b) => {

src/libsyntax/ext/deriving/generic/mod.rs

@@ -996,7 +996,7 @@ impl<'a> MethodDef<'a> {
             let arms : Vec<ast::Arm> = variants.iter().enumerate()
                 .map(|(index, &variant)| {
                     let pat = variant_to_pat(cx, sp, &*variant);
-                    let lit = ast::LitUint(index as u64, ast::TyU);
+                    let lit = ast::LitInt(index as u64, ast::UnsignedIntLit(ast::TyU));
                     cx.arm(sp, vec![pat], cx.expr_lit(sp, lit))
                 }).collect();
 

src/libsyntax/ext/quote.rs

@@ -189,16 +189,17 @@ pub mod rt {
         (signed, $t:ty, $tag:ident) => (
             impl ToSource for $t {
                 fn to_source(&self) -> String {
-                    let lit = dummy_spanned(ast::LitInt(*self as i64, ast::$tag));
-                    pprust::lit_to_string(&lit)
+                    let lit = ast::LitInt(*self as u64, ast::SignedIntLit(ast::$tag,
+                                                                          ast::Sign::new(*self)));
+                    pprust::lit_to_string(&dummy_spanned(lit))
                 }
             }
         );
         (unsigned, $t:ty, $tag:ident) => (
             impl ToSource for $t {
                 fn to_source(&self) -> String {
-                    let lit = dummy_spanned(ast::LitUint(*self as u64, ast::$tag));
-                    pprust::lit_to_string(&lit)
+                    let lit = ast::LitInt(*self as u64, ast::UnsignedIntLit(ast::$tag));
+                    pprust::lit_to_string(&dummy_spanned(lit))
                 }
             }
         );

src/libsyntax/parse/mod.rs

@@ -515,31 +515,13 @@ pub fn integer_lit(s: &str, sd: &SpanHandler, sp: Span) -> ast::Lit_ {
     debug!("parse_integer_lit: {}", s);
 
     if s.len() == 1 {
-        return ast::LitIntUnsuffixed((s.char_at(0)).to_digit(10).unwrap() as i64);
+        let n = (s.char_at(0)).to_digit(10).unwrap();
+        return ast::LitInt(n as u64, ast::UnsuffixedIntLit(ast::Sign::new(n)));
     }
 
     let mut base = 10;
     let orig = s;
-
-    #[deriving(Show)]
-    enum Result {
-        Nothing,
-        Signed(ast::IntTy),
-        Unsigned(ast::UintTy)
-    }
-
-    impl Result {
-        fn suffix_len(&self) -> uint {
-            match *self {
-                Nothing => 0,
-                Signed(s) => s.suffix_len(),
-                Unsigned(u) => u.suffix_len()
-            }
-        }
-    }
-
-    let mut ty = Nothing;
-
+    let mut ty = ast::UnsuffixedIntLit(ast::Plus);
 
     if s.char_at(0) == '0' {
         match s.char_at(1) {
@@ -556,13 +538,13 @@ pub fn integer_lit(s: &str, sd: &SpanHandler, sp: Span) -> ast::Lit_ {
 
     let last = s.len() - 1;
     match s.char_at(last) {
-        'i' => ty = Signed(ast::TyI),
-        'u' => ty = Unsigned(ast::TyU),
+        'i' => ty = ast::SignedIntLit(ast::TyI, ast::Plus),
+        'u' => ty = ast::UnsignedIntLit(ast::TyU),
         '8' => {
             if s.len() > 2 {
                 match s.char_at(last - 1) {
-                    'i' => ty = Signed(ast::TyI8),
-                    'u' => ty = Unsigned(ast::TyU8),
+                    'i' => ty = ast::SignedIntLit(ast::TyI8, ast::Plus),
+                    'u' => ty = ast::UnsignedIntLit(ast::TyU8),
                     _ => { }
                 }
             }
@@ -570,8 +552,8 @@ pub fn integer_lit(s: &str, sd: &SpanHandler, sp: Span) -> ast::Lit_ {
         '6' => {
             if s.len() > 3 && s.char_at(last - 1) == '1' {
                 match s.char_at(last - 2) {
-                    'i' => ty = Signed(ast::TyI16),
-                    'u' => ty = Unsigned(ast::TyU16),
+                    'i' => ty = ast::SignedIntLit(ast::TyI16, ast::Plus),
+                    'u' => ty = ast::UnsignedIntLit(ast::TyU16),
                     _ => { }
                 }
             }
@@ -579,8 +561,8 @@ pub fn integer_lit(s: &str, sd: &SpanHandler, sp: Span) -> ast::Lit_ {
         '2' => {
             if s.len() > 3 && s.char_at(last - 1) == '3' {
                 match s.char_at(last - 2) {
-                    'i' => ty = Signed(ast::TyI32),
-                    'u' => ty = Unsigned(ast::TyU32),
+                    'i' => ty = ast::SignedIntLit(ast::TyI32, ast::Plus),
+                    'u' => ty = ast::UnsignedIntLit(ast::TyU32),
                     _ => { }
                 }
             }
@@ -588,8 +570,8 @@ pub fn integer_lit(s: &str, sd: &SpanHandler, sp: Span) -> ast::Lit_ {
         '4' => {
             if s.len() > 3 && s.char_at(last - 1) == '6' {
                 match s.char_at(last - 2) {
-                    'i' => ty = Signed(ast::TyI64),
-                    'u' => ty = Unsigned(ast::TyU64),
+                    'i' => ty = ast::SignedIntLit(ast::TyI64, ast::Plus),
+                    'u' => ty = ast::UnsignedIntLit(ast::TyU64),
                     _ => { }
                 }
             }
@@ -597,21 +579,22 @@ pub fn integer_lit(s: &str, sd: &SpanHandler, sp: Span) -> ast::Lit_ {
         _ => { }
     }
 
-
-    s = s.slice_to(s.len() - ty.suffix_len());
-
     debug!("The suffix is {}, base {}, the new string is {}, the original \
            string was {}", ty, base, s, orig);
 
+    s = s.slice_to(s.len() - ty.suffix_len());
+
     let res: u64 = match ::std::num::from_str_radix(s, base) {
         Some(r) => r,
         None => { sd.span_err(sp, "int literal is too large"); 0 }
     };
 
+    // adjust the sign
+    let sign = ast::Sign::new(res);
     match ty {
-        Nothing => ast::LitIntUnsuffixed(res as i64),
-        Signed(t) => ast::LitInt(res as i64, t),
-        Unsigned(t) => ast::LitUint(res, t)
+        ast::SignedIntLit(t, _) => ast::LitInt(res, ast::SignedIntLit(t, sign)),
+        ast::UnsuffixedIntLit(_) => ast::LitInt(res, ast::UnsuffixedIntLit(sign)),
+        us@ast::UnsignedIntLit(_) => ast::LitInt(res, us)
     }
 }
 

src/libsyntax/parse/parser.rs

@@ -34,7 +34,7 @@ use ast::{Ident, NormalFn, Inherited, Item, Item_, ItemStatic};
 use ast::{ItemEnum, ItemFn, ItemForeignMod, ItemImpl};
 use ast::{ItemMac, ItemMod, ItemStruct, ItemTrait, ItemTy, Lit, Lit_};
 use ast::{LitBool, LitChar, LitByte, LitBinary};
-use ast::{LitNil, LitStr, LitUint, Local, LocalLet};
+use ast::{LitNil, LitStr, LitInt, Local, LocalLet};
 use ast::{MutImmutable, MutMutable, Mac_, MacInvocTT, Matcher, MatchNonterminal};
 use ast::{MatchSeq, MatchTok, Method, MutTy, BiMul, Mutability};
 use ast::{NamedField, UnNeg, NoReturn, UnNot, P, Pat, PatEnum};
@@ -1889,7 +1889,7 @@ impl<'a> Parser<'a> {
     pub fn mk_lit_u32(&mut self, i: u32) -> Gc<Expr> {
         let span = &self.span;
         let lv_lit = box(GC) codemap::Spanned {
-            node: LitUint(i as u64, TyU32),
+            node: LitInt(i as u64, ast::UnsignedIntLit(TyU32)),
             span: *span
         };
 

src/libsyntax/print/pprust.rs

@@ -2415,15 +2415,25 @@ impl<'a> State<'a> {
                 word(&mut self.s, res.as_slice())
             }
             ast::LitInt(i, t) => {
-                word(&mut self.s,
-                     ast_util::int_ty_to_string(t, Some(i)).as_slice())
-            }
-            ast::LitUint(u, t) => {
-                word(&mut self.s,
-                     ast_util::uint_ty_to_string(t, Some(u)).as_slice())
-            }
-            ast::LitIntUnsuffixed(i) => {
-                word(&mut self.s, format!("{}", i).as_slice())
+                match t {
+                    ast::SignedIntLit(st, ast::Plus) => {
+                        word(&mut self.s,
+                             ast_util::int_ty_to_string(st, Some(i as i64)).as_slice())
+                    }
+                    ast::SignedIntLit(st, ast::Minus) => {
+                        word(&mut self.s,
+                             ast_util::int_ty_to_string(st, Some(-(i as i64))).as_slice())
+                    }
+                    ast::UnsignedIntLit(ut) => {
+                        word(&mut self.s, ast_util::uint_ty_to_string(ut, Some(i)).as_slice())
+                    }
+                    ast::UnsuffixedIntLit(ast::Plus) => {
+                        word(&mut self.s, format!("{}", i).as_slice())
+                    }
+                    ast::UnsuffixedIntLit(ast::Minus) => {
+                        word(&mut self.s, format!("-{}", i).as_slice())
+                    }
+                }
             }
             ast::LitFloat(ref f, t) => {
                 word(&mut self.s,

src/test/compile-fail/lint-type-overflow.rs

@@ -48,6 +48,9 @@ fn main() {
     let x: i32 = -2147483649; //~ error: literal out of range for its type
     let x = -2147483649_i32; //~ error: literal out of range for its type
 
+    let x = 9223372036854775808_i64; //~ error: literal out of range for its type
+    let x = 18446744073709551615_i64; //~ error: literal out of range for its type
+
     let x = -3.40282348e+38_f32; //~ error: literal out of range for its type
     let x =  3.40282348e+38_f32; //~ error: literal out of range for its type
     let x = -1.7976931348623159e+308_f64; //~ error: literal out of range for its type

src/test/compile-fail/oversized-literal.rs

@@ -8,6 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// compile-flags: -D type-overflow
-
-fn main() { println!("{}", 300u8); } //~ error: literal out of range for its type
+fn main() {
+    println!("{}", 18446744073709551616u64);  //~ error: int literal is too large
+}

src/test/run-pass/big-literals.rs

@@ -15,6 +15,4 @@ pub fn main() {
     assert_eq!(18446744073709551615u64, (-1 as u64));
 
     assert_eq!(-2147483648i32 - 1i32, 2147483647i32);
-    assert_eq!(-9223372036854775808i64 - 1i64, 9223372036854775807i64);
-    assert_eq!(-9223372036854775808i - 1, 9223372036854775807);
 }